1. Field of the Invention
The present invention relates to a car navigation system.
2. Description of the Related Art
In recent years, a variety of car navigation systems have been developed. Such a car navigation system can be classified according to a screen guide method into a full map navigation system and a turn-by-turn navigation system. The former is designed to guide a driver to a destination by displaying a current path and location on a map, while the latter is designed to guide the driver to the destination by issuing a simple directional command such as a left turn, a right turn and a straight drive instructions considering the current location and driving direction.
As is well known, the turn-by-turn navigation system is suitable to a person who is not familiar with reading a map or to a case where a display screen is too small to display a sufficient range of the map.
FIG. 1 shows a screen example of a prior full map navigation system.
Referring to FIG. 1, the screen shows that the car successively makes a right turn, a left turn, a right turn, and a right turn to reach the destination. That is, since the full map navigation system displays a path that would give a driver a direction where the car must be advanced at a glance so that the driver can properly cope with a next path guide.
Meanwhile, the screen guide of the turn-by-turn navigation system is however designed to focus on the current point of time. FIG. 2 shows a screen example of a prior turn-by-turn navigation system.
As shown in FIGS. 2a through 2c, the turn-by-turn navigation system shows only a current directional guide to a right-turn or a left-turn. That is, the turn-by-turn navigation system has a disadvantage of not providing a next guidance of the current guidance. The system provide a next guidance after the car advances by a predetermined distance from the current position. As shown in FIGS. 2a through 2c, a predetermined distance 21 required for the direction change and direction information 22 are displayed on the screen.
When the time and distance for coping with a lane change are sufficient to perform the next guidance after following the current guidance, the driver may not get into trouble. However, when the user does not have any information on the current driving road and the distance to the next direction change point is too short for the driver to cope with the next guidance, the driver may get into trouble. This may sometimes cause a fatal accident.